Why it worked
The video leverages a surprising and unconventional use of common household items (coffee grounds and glue) to achieve a desirable aesthetic result (refreshed wood finish), tapping into the DIY and life hack trends.
Summary
The video demonstrates how to create a homemade wood varnish by mixing PVA glue with coffee grounds, oil, and alcohol. The resulting mixture is then applied to a wooden door to give it a darker, refreshed look, presented as a secret technique used by carpenters.